Ninety-two nursing home residents aged 65 years or older and BMI <25 were randomly assigned to the intervention or control groups. Subjects in the treatment group received a soy-protein-based nutritional supplement, if his/her BMI was <24kg/m2 and nutritional score was <24 according to the Mini Nutritional Assessment. The supplementation would be suspended if both conditions were not met. At baseline and every 4 weeks up to 24 weeks, thereafter, all subjects were measured for anthropometric parameters. At baseline, 12 weeks and 24 weeks subjects were measured for blood biochemical indicators, handgrip strength and Barthel's index.